Differential Diagnosis for ST after Oral Sex in a Female

• Single most likely diagnosis
  • Gonorrhea: This is a common sexually transmitted infection (STI) that can be transmitted through oral sex. The symptoms can include sore throat, which aligns with the presentation after oral sex.
• Other Likely diagnoses
  • Chlamydia: Similar to gonorrhea, chlamydia is another STI that can cause symptoms after oral sex, including a sore throat.
  • Herpes Simplex Virus (HSV): HSV can cause oral and genital herpes, and transmission can occur through oral sex, leading to symptoms like cold sores or genital lesions.
  • Syphilis: This STI has various stages and can be transmitted through oral sex, with primary syphilis potentially causing a sore or ulcer.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • HIV: Although less likely to be directly diagnosed from a sore throat after oral sex, HIV testing is crucial in anyone with a new STI diagnosis due to the potential for co-infection.
  • Pharyngeal Cancer: Though rare and more associated with long-term risks (like HPV infection), any persistent or unusual throat symptoms should prompt consideration of this diagnosis to ensure early detection and treatment.
• Rare diagnoses
  • Lymphogranuloma Venereum (LGV): This is a rare STI caused by certain strains of chlamydia, which can lead to symptoms like swollen lymph nodes and can be transmitted through oral sex.
  • Hepatitis B and C: These viral infections can be transmitted through bodily fluids, including potentially through oral sex, especially if there are cuts or sores in the mouth. However, they are less commonly associated with immediate symptoms like a sore throat after oral sex.